两个绝对路径！写个函数，找出两者相对路径(1.php相对于2) $a = ＂/a/b/c/1.php＂

//这两个是绝对路径！写个函数，找出两者相对路径(1.php相对于2)
$a = "/a/b/c/1.php";
$b = "/a/b/f/2.php";
function getpathinfo($a, $b)
{
    $a2array = explode('/', $a);
    $b2array = explode('/', $b);
    $acount = count($a2array);//计算出a数组的总数
    $bcount = count($b2array);//计算出b数组的总数	总共能分出来6个，我们去除第0个和第5个
    $pathinfo = "";
    for ($i = 1; $i <= $bcount - 2; $i++) {
        if ($a2array[$i] != $b2array[$i]) {
            for ($m = $i; $m <= $acount - 2; $m++) {            //$i=3   $m = 8   $m = 6
                $pathinfo .= "../";
                //echo $pathinfo;
            }
//			echo $pathinfo;
//			echo "";
            if ($pathinfo != "") {        //如果不等于空的时候去除/
                $pathinfo = rtrim($pathinfo, "/");                    //去除当前字符串最后的
            }
            for ($k = $i; $k <= $bcount - 2; $k++) {
                $pathinfo .= "/" . $b2array[$k];
            }
            break;
        }
    }
    return $pathinfo;
}
echo '';
echo getpathinfo($a, $b);